Screen grid for power tubes and method of making the same



 

1. A METHOD OF MAKING A SCREEN GRID OF CUP SHAPE COMPRISING: (A) FORMING FROM A SHEET METAL BLANK A CENTRALLY LOCATED END WALL MEMBER AND A MULTIPLICITY OF GRID BARS OF SUBSTANTIALLY UNIFORM CROSS SECTIONAL SIZE INTEGRAL WITH AND RADIATING FROM THE PERIPHERY OF SAID END WALL MEMBER; (B) BENDING AND HOLDING SAID BARS SO THAT THEY EXTEND IN SUBSTANTIALLY PARALLEL RELATION ONE TO THE OTHERS IN THE SHAPE OF A TUBULAR GRID AT ONE SIDE OF SAID END MEMBER, AND (C) CONNECTING THE ENDS OF SAID BARS REMOTE FROM SAID END MEMBER TO A METAL RING, PROVIDING AN ANNULAR BASE FOR SUPPORTING THE GRID. 